#include<stdio.h>
int main()
{
    int score;
    char grade;
    printf("Please input a score:");
    scanf("%d",&score);
    if(score>=90)
    {
        grade = 'A';
    }
    else if(score>=60&&score<90)
    {
        grade = 'B';
    }
    else
    {
        grade = 'C';
    }
    printf("%d belongs to %c\n",score,grade);
    return 0;
}